For those following the saga.... I had purchased an autozone rebuilt power brake booster last summer. I never could get it to work right in that the pedal would not return all the way. So I replaced it under warranty with another one.

After measuring the pushrods, the pushrod on the new one was almost exactly 1 inch longer than the one that I was returning. :mad :mad

It's not adjustable and it doesn't need to be.

It bolted right up and into place. Once I attached it to the pedal, it still pushed the brake light (the old one didn't).

So... Lesson learned.... measure the push rods on the booster prior to replacing with a rebuilt one. It does make a difference. :withstupid:

 

Well glad to hear you have it straightened out Mike. Now you should be back on the road by Spring!
Gary

 

When you say "push rod" are you refering to the metal rod that comes from the vaccuummee (sp) brake booster and pushes the master cylnder?

If so, I have learned that there was a production change around 73, in the length of the rod. Most places like Eeeck-Itsgoingtocosthowmuch-lers will lump that part in the 68 to 82 range while it needs to be split into a 68 to 73 and 74 to 82 ranges.

Im happy you had sucess
cheers
chad

 

71, the rod that I am referring to is the pedal to the booster rod. The one from the booster to the master cylinder was adjustable, but that didn't help the problem that the one going to the pedal was too short. :(

Basically, when I let off the pedal, the rod would come out as much as it could, but that wasn't enough to hit the brake light switch to turn it off. The replacement one is long enough. :eek:

One problem down, now on to the next. :)

 

THat's typical of junk zone, dizcownt, pee Boyz... etc.ect.

 

Phoenix
Good to hear you got it righted. Ill probably be ordering mine very soon.

Hows the rest of the brake resto?

Brent...

 

Glad you got it figured out and thanks for sharing. This story will stick in my memory. :cheers:

 

Phoenix
If you dont mind, could you look on your papers for this and see what part number it is that they gave to you that was the good booster?

I have searched and come up with only: A1 Cardone # 54-81200.

This part is on the auto zone site & the checker auto parts site. They must be both buying from the same sources.

What Im worried about is there are 2 different models of power booster a 68-76 model and a 77-82 model. Neither web-site differentiates between years for 68-82.

I tried to send you an IM but I always get a CF "notepad" page instead of the IM window????

Brent...

 

Brent, that is the correct model number. The problem is that the model number was the same on the bad one too. :( There was actually a very small difference in the overall shape of the booster. I wouldn't have noticed if I didn't hold them up side by side and compare.

My advice would be to definitely compare the one that you are buying with the original one. It seems to work well now, but man what a pain.

The only good thing is that the last 2 times that I had to change the booster, the entire dash and steering column was out so it was easy to get to the bolts.

 

Lots of people have this problem.... you have to click on the words "Send IM" not the icon next to them. Joe

 

Thanks for the post. I'm starting mine tonight and will compare before reinstalling. The forum strikes again (with needed help) :cheers:

 

Phoenix
Thanks for your reply. I guess thats a known thing to do is to compare before you start doing any reassembly.

Best Regards,
Brent....

 

Brent, what really ticks me off is that I actually DID compare the first one that I bought. It was not really obvious that there was any difference. At least not until I tried to install it. :mad The pushrod was only about an inch shorter, but since a large portion of the rod is inside the booster, I guess that I just assumed that it was correct.

Once again... when you assume :yesnod: :yesnod:

Hopefully I'll learn from this. :D

 

I know that this is a very old thread, but I just fell into a similar trap installing a "GM licensed" booster from Duntov motors, which is made by MBM Products, into my '73.

Using the highly reliable eyeball method, the booster to pedal pushrod length looked the same on the replacement as the OEM booster I removed from the car, but after careful measurements (after installing then removing the new booster, duh!) the point of the pin placement in the clevis of the replacement booster was about 3/16" closer to the booster than the OEM pushrod. Even though this seems like a small difference, it was still enough to lower the pedal beyond the range of adjustment of the brake lamp switch.

Additionally, the studs which pass through the firewall are slightly larger in diameter than the OEM ones, making the nuts larger as well, which greatly increased the difficulty of getting the nuts back on (and back off) because of the tight tolerances under the dash.

The studs which attach the master cylinder to the booster are slightly larger as well, making it nearly impossible to push the MC into place.

The third difference in this unit is that the pushrod going from the booster to the MC is not adjustable. Maybe that's not really a problem, but I don't like it.

When I spoke to the guy at Duntov, he had never heard of any of these issues before, and wasn't really much help. Unfortunately, I've had the parts for several months, and like some kind of retard, couldn't find the paperwork. Also, there are no identifying numbers on the MBM booster anywhere that I can find.

I didn't want to fabricate a longer clevis, so I decided to order a remanufactured booster from VBP, which arrived in just 4 days. It looks exactly like my original unit, except for the color. The pushrod to the pedal is the same length as my original, and also like the original, the pushrod to the MC is adjustable. The only shortcoming of the rebuilt booster from VBP is that it does not come with a clevis.

So... Another valuable lesson re-learned again. It doesn't matter where you buy your parts from, because you can always wind up with something that's incorrect, and only an idiot with a huge pile of parts sitting in the corner of his garage for months doesn't save his receipts.

Now if I can just figure out where that liquid on the garage floor is coming from...